So every A tier unob (lightning platinum, old scr, pumpkin tw, rainbow cosmic Luigi, John Doe, cosmic herobrine) being worth one unob stand? I dont see it, even if S tiers like Herobrine, Old Pot Platinum, Old Celeb Pot, Discord Verified DPP are found in a server, they are still at most worth 4-5 A tiers. I highly doubt anyone would ask for every single A tier.
Rather since you claim you have less space (only 4 spaces which Im guessing are already filled with all A tier unobs), either transfer the remaining A tier unobs to alt accounts and write it down somewhere so you dont forget or trade each A tier for 1-2 B tiers or 2-3 C tiers. Although by downgrading you are both losing value and acquiring more stands for less space. Best option is to store on alts or to give away A tier unobs you dont want ( I gave away my lightning platinum to someone random bec I ran out of space and I had too many alts already).